One vertex per element, one color per generator, with an edge from x to x·s.
(5,6,9,10)(7,8,11,12)(13,14,16,17)(15,19,20,18)(21,22,26,28)(23,24,27,25)(2,4)(6,10)(8,12)(13,14)(15,19)(16,17)(18,20)(21,23,26,27)(22,24,28,25)(1,2,3,4)(6,10)(7,11)(14,17)(18,19)(21,24,26,25)(22,23,28,27)(5,7)(6,8)(9,11)(10,12)(13,14)(15,18)(16,17)(19,20)(21,22)(23,24)(25,27)(26,28) involution — undirected(5,8)(6,7)(9,12)(10,11)(13,15)(14,18)(16,20)(17,19)(21,25,26,24)(22,27,28,23)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.